Highly dispersed MoO_(x)-Ru/C bimetallic catalyst for efficient hydrogenolysis of esters to alkanes  

高分散MoO_(x)-Ru/C双金属催化剂催化酯类化合物高效氢解制备烷烃

作　　者：Xincheng Cao Jiaping Zhao Feng Long Peng Liu Yuguo Dong Zupeng Chen Junming Xu Jianchun Jiang 曹新诚;赵佳平;龙锋;刘朋;董煜国;陈祖鹏;徐俊明;蒋剑春(中国林业科学研究院林产化学工业研究所,江苏省生物质能源与材料重点实验室,国家林业和草原局林产化学工程重点实验室,林木生物质低碳高效利用国家工程研究中心,江苏南京210042;南京林业大学化学工程学院,林业资源高效加工利用协同创新中心,林产化学与材料国际创新高地,江苏南京210037)

机构地区：[1]Institute of Chemical Industry of Forest Products,Chinese Academy of Forestry,Key Laboratory of Biomass Energy and Material,Jiangsu Province,National Engineering Laboratory for Biomass Chemical Utilization,Key and Open Laboratory on Forest Chemical Engineering,SFA,Nanjing 210042,Jiangsu,China [2]Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources,International Innovation Center for Forest Chemicals and Materials,Nanjing Forestry University,Nanjing 210037,Jiangsu,China

出　　处：《Chinese Journal of Catalysis》2025年第4期256-266,共11页催化学报(英文)

基　　金：国家重点研发项目(2019YFB1504005,2019YFB1504000);国家自然科学基金(32301548);国家资助博士后研究人员计划(GZC20230878).

摘　　要：The efficient hydrogenolysis of esters to alkanes is the key protocol for producing advanced biofuels from renewable plant oils or fats.Due to the low reactivity of the carbonyl group in esters,a high reaction temperature(>250℃)is the prerequisite to ensure high conversion of esters.Here,we report a highly dispersed MoO_(x)-Ru/C bimetallic catalyst for the efficient hydrogenolysis of esters to alkanes under 150°C.The optimal catalyst exhibits>99%conversion of methyl stearate and 99%selectivity to diesel-range alkanes,reaching a high rate of up to 2.0 mmol gcat^(–1)h^(–1),5 times higher than that of Ru/C catalyst(MoO_(x)/C is inert).Integrated experimental and theoretical investigations attribute the high performance to the abundant MoO_(x)-Ru interfacial sites on the catalyst surface,which offers high activity for the C–O cleavage of esters.Furthermore,the dispersed MoO_(x)species significantly weaken the hydrocracking activity of the metallic Ru for C–C bonds,thus yielding alkane products without carbon loss.This study provides a facile and novel strategy for the design of high-performance heterogeneous catalysts for the hydrodeoxygenation of biomass-derived esters to alkane products.催化酯类化合物加氢脱氧转化为烷烃是利用生物油脂生产先进液体生物燃料的关键一步.然而,由于酯类化合物中羰基官能团反应性较低,导致反应温度通常较高(>250℃).高的反应温度不仅易造成油脂分子发生C-C键断裂副反应,而且会导致催化剂烧结和团聚,降低催化剂活性.因此,研制高效稳定的油脂加氢脱氧催化剂非常必要.将可还原金属氧化物(如WO_(x),MoO_(x)和ReO_(x)等)锚定到贵金属(例如Pt,Ir和Rh)表面,可以有效地促进生物质含氧化合物加氢脱氧.然而,由于金属氧化物分散性较差,导致催化剂加氢活性降低.本文合成了一系列高分散MO_(x)-Ru/C(M=Fe,Sn,Mo和W等)双金属催化剂,用于催化酯类化合物在低温下(150℃)加氢脱氧转化为长链烷烃.催化剂性能测试结果表明,MoO_(x)-Ru/C催化剂呈现出最优的催化活性,在150°C和3.0 MPa H_(2)的温和条件下,反应5.0 h后,硬脂酸甲酯可以定量转化为长链烷烃,催化活性是Ru/C催化剂的5倍.X-射线衍射、高分辨透射电镜、球差扫描透射电镜和CO-脉冲吸附结果表明,负载的Mo物种主要以高分散的形式分散在金属Ru表面.同步辐射X射线吸收光谱和吡啶红外测试结果表明,高分散的Mo主要以三配位的形式存在于Ru/C表面上;MoO_(x)的加入极大地增加了Ru/C催化剂的Brönsted和Lewis酸位点浓度.金属Ru,Brönsted和Lewis酸位点三者之间的协同催化作用有效地促进了脂肪酯在低温下加氢脱氧.除了在催化长链脂肪酸酯外,MoO_(x)-Ru/C也可以高效地催化环状酯(如丙位十二内脂和丁位十一内酯)、脂肪酸甘油酯和真实油脂如地沟油加氢脱氧转化为相应的烃类产物.另一方面,通过探究脂肪酯在催化剂表面上的加氢反应动力学,发现Ru/C催化剂易造成脂肪酯发生脱羰和裂解反应,而MoO_(x)-Ru/C催化剂主要促进酯类化合物发生加氢脱氧反应,产物多数为无碳原子损失的Cn烷烃(选择性约为77%

关 键 词：Bimetallic catalyst Interface engineering HYDRODEOXYGENATION Fatty esters Diesel-range alkanes 

分 类 号：O643.36[理学—物理化学]